Re: Significantly larger toast tables on 8.4?
Alex Hunsaker <badalex@gmail.com>
From: "Alex Hunsaker" <badalex@gmail.com>
To: "Tom Lane" <tgl@sss.pgh.pa.us>
Cc: "Robert Haas" <robertmhaas@gmail.com>, "Stephen R. van den Berg" <srb@cuci.nl>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2009-01-03T02:27:46Z
Lists: pgsql-hackers
On Fri, Jan 2, 2009 at 18:30, Tom Lane <tgl@sss.pgh.pa.us> wrote: > "Alex Hunsaker" <badalex@gmail.com> writes: >> On Fri, Jan 2, 2009 at 11:44, Tom Lane <tgl@sss.pgh.pa.us> wrote: >>> An easy way to prove or disprove the point would be to go into >>> src/backend/utils/adt/pg_lzcompress.c, and change the second entry >>> in strategy_default_data from "1024 * 1024" to "INT_MAX", > >> And the toast file size is *drum roll* 167M. > > Hmmm ... so that's a lot closer to the original 145M, but it still > seems like there's something else going on. It looks like the other > thing we changed that might result in not compressing things was to > increase the third entry (minimum compression rate) from 20% to 25%. > Could you try it with that value also changed back? With it back to 20% its now back to 145M.